I want to update readers on the changes between the 1-year estimate data reported in that article (from 2008) and the most recent 1-year estimate data (from 2009). Percentages represent workers in the City of Chicago aged 16 and older riding bicycles to work.

We should be concerned about the possibleÂ decrease in the percentage of women riding bicycles to work, especially as the population size increased. The margin of error also decreased, thus suggesting an improvement in the accuracy of the data.Â There have already been many discussions (mine, others) as to why it is important to encourage women to ride bicycles and also what the woman cycling rate tells us about our cities and policies. If the decrease continues we must discover the causes.

But Table 1 doesn’t tell the full story.

As Matt points out in the comments below, the number of surveys returned for 1-year estimates is smaller than that from the Decennial Census. Therefore, I took a look at the two 3-year estimates available, each having a larger sample size than the 1-year estimates (see Table 2). The data below seem to show the opposite change than seen in Table 1: that the number of women bicycling to work has increased. The crux of our quandary is sample size. The sample size is the number of peopleÂ who are asked, “How did this person usually get to work LAST WEEK?”

The number of discrete females who bike to work has decreased in the most recent survey (2007-2009) while the total number of workers 16 and older has increased, giving females bicycling to work a smaller share than the previous survey (2006-2008). We must be careful to also note the margin of error for females bicycling to work is Â±499.

Matt suggested that sustainable transportation advocates “push for higher sampling” to reduce “data noise” and increase the accuracy of how this data represents actual conditions. I agree – I’d also like more data on all trips, and not just those made to go to work. Household travel surveys attempt to reveal more information about a region’s transportation.

One of the two overall goals of the Bike 2015 Plan is “to increase bicycle use, so that 5 percent of all trips less than five miles are by bicycle.” Unfortunately, the Plan doesn’t provide baseline data for this metric, but we can make some inferences (there will probably be no data for this in 2015, either). The CMAP Household Travel Survey summary from 2008 says that the mean trip distance (for all trips) for Cook County households is 4.38 miles (under five miles). The same survey says that for all trips, 1.3% were taken by bike. These can be our metrics. *See below for men/women breakdown. Note that no data for “all trips” exists for the City of Chicago.

We will not achieve the Bike 2015 Plan goal unless we do something about the conditions that promote and increase bicycling. Achieving the goals in the Bike 2015 Plan is not one group or agency’s responsibility. The Plan should be seen as a manifestation of what can and should be done for bicycling in Chicago and we all have a duty to promote its objectives.

Please leave a comment below for why you think the rate of women who bike to work has stayed flat and decreased, or what you think we can do to change this. Does it have to do with the urban environment, or are the reasons closer to home?

*The same survey also said: Cook County males used the bike for 1.9% of all trips. Cook County females used the bike for 0.8% of all trips.

Table 1 data comes from the 1-year estimates from the American Community survey, table S0801, Commuting Characteristics by Sex for the City of Chicago (permalink), which is a summary table of data in table B08006.Â Table 2 data directly from American Community Survey tableÂ B08006.

Some of us lost jobs between ’08 and ’09. I stopped biking to work when there was no work to bike to.

Oh, and ’08 was the year of high gas prices. I’ll bet anything a lot of women got right back into their cars as soon as it was (supposedly) affordable to do so again, or as soon as they could afford to buy new cars that were more fuel efficient. (On that note, I wonder if Cash for Clunkers was also a factor.)

I have a hunch that men start bike commuting and get hooked for life, whereas women see it more as a temporary solution to some immediate problem until conditions favor the status quo again.

http://www.stevevance.net/planning Steven Vance

I can always count on you to come up with unique ideas. Me? I’m pretty middle of the road, or I just depend on the same ol’ urban planning talking points of the current year.

Thanks for your input.

http://www.stevevance.net/planning Steven Vance

I updated the article to provide a better response to address the pitfalls (that I fell in) of reporting statistics.

http://jmd1125.blogspot.com Jennifer

Yes, I see that now. Thanks!

Seriously, I tried to consider what I’d do if I were a normal person who got laid off in ’08, and what I came up with was that the most stable full-time job I could find would probably be in some far-flung exurb with no Metra station and no Pace route but lots of shiny new federal stimulus road expansion projects. I’d have to go back to driving to work every day because cycling would be impractical to impossible (a function of distance, Metra rules, road configurations, and automobile traffic speed/volume), but luckily gas prices are back down, and I could afford a new car with better mileage with the government rebate, so it’s all good.

I have no idea if this is what actually happened to people other than me, but I seem to recall hearing this story several times in the recent past: I used to bike to work, but then I had to get a new job that’s farther away/inconveniently located, and now I can’t anymore.

http://www.stevevance.net/planning Steven Vance

Check out the updated data in Table 2 (3-year estimates from 2007-2009 were added to show a decrease in women cycling to work, based on a larger sample size than 1-year estimate).

http://jmd1125.blogspot.com Jennifer

Some of us lost jobs between ’08 and ’09. I stopped biking to work when there was no work to bike to.

Oh, and ’08 was the year of high gas prices. I’ll bet anything a lot of women got right back into their cars as soon as it was (supposedly) affordable to do so again, or as soon as they could afford to buy new cars that were more fuel efficient. (On that note, I wonder if Cash for Clunkers was also a factor.)

I have a hunch that men start bike commuting and get hooked for life, whereas women see it more as a temporary solution to some immediate problem until conditions favor the status quo again.

http://www.stevevance.net/planning Steven Vance

I can always count on you to come up with unique ideas. Me? I’m pretty middle of the road, or I just depend on the same ol’ urban planning talking points of the current year.

Thanks for your input.

http://www.stevevance.net/planning Steven Vance

I updated the article to provide a better response to address the pitfalls (that I fell in) of reporting statistics.

http://jmd1125.blogspot.com Jennifer

Yes, I see that now. Thanks!

Seriously, I tried to consider what I’d do if I were a normal person who got laid off in ’08, and what I came up with was that the most stable full-time job I could find would probably be in some far-flung exurb with no Metra station and no Pace route but lots of shiny new federal stimulus road expansion projects. I’d have to go back to driving to work every day because cycling would be impractical to impossible (a function of distance, Metra rules, road configurations, and automobile traffic speed/volume), but luckily gas prices are back down, and I could afford a new car with better mileage with the government rebate, so it’s all good.

I have no idea if this is what actually happened to people other than me, but I seem to recall hearing this story several times in the recent past: I used to bike to work, but then I had to get a new job that’s farther away/inconveniently located, and now I can’t anymore.

http://www.stevevance.net/planning Steven Vance

Check out the updated data in Table 2 (3-year estimates from 2007-2009 were added to show a decrease in women cycling to work, based on a larger sample size than 1-year estimate).

http://www.facebook.com/profile.php?id=678847491 Gin Kilgore

Surprising. In my limited range of observation, there seem to be many more women biking. Perhaps if we were further along in implementing some of the 2015 projects, such as Bike Boulevards, more people, inc women, would be biking?

http://www.stevevance.net/planning Steven Vance

I agree.

A bike boulevard, and other innovative bikeways called for in the Bike 2015 Plan, keeps people riding bikes in traffic but prioritizes/rearranges roadway elements to increase their safety.

People choose off-street trails because of their perceived safety (not mixing with cars), but some research shows that off-street trails are more dangerous than riding with car traffic.

Note how I point out two datasets. The table and chart are based on worker commutes by bicycle. In the narrative, I suggest using the CMAP Househould Travel survey as a metric to know when we’ve reached our goal of 5% of all trips under 5 miles. Currently, we’re at 1.3% in Cook County. No data for “all trips” exists for the City of Chicago.

http://www.facebook.com/profile.php?id=678847491 Gin Kilgore

Totally with you on real and perceived risks/barriers. Hence my work with Bike Winter and my overall “you can do it!” zeal re: dressing up, carrying stuff, etc.

http://www.facebook.com/profile.php?id=678847491 Gin Kilgore

Surprising. In my limited range of observation, there seem to be many more women biking. Perhaps if we were further along in implementing some of the 2015 projects, such as Bike Boulevards, more people, inc women, would be biking?

http://www.stevevance.net/planning Steven Vance

I agree.

A bike boulevard, and other innovative bikeways called for in the Bike 2015 Plan, keeps people riding bikes in traffic but prioritizes/rearranges roadway elements to increase their safety.

People choose off-street trails because of their perceived safety (not mixing with cars), but some research shows that off-street trails are more dangerous than riding with car traffic.

Note how I point out two datasets. The table and chart are based on worker commutes by bicycle. In the narrative, I suggest using the CMAP Househould Travel survey as a metric to know when we’ve reached our goal of 5% of all trips under 5 miles. Currently, we’re at 1.3% in Cook County. No data for “all trips” exists for the City of Chicago.

http://www.facebook.com/profile.php?id=678847491 Gin Kilgore

Totally with you on real and perceived risks/barriers. Hence my work with Bike Winter and my overall “you can do it!” zeal re: dressing up, carrying stuff, etc.

http://www.facebook.com/profile.php?id=513686360 Matt Zanon

A one-digit change in a one-significant-figure statistic implies nothing about anyone’s biking. ACS is a sample, not a census. Have you investigated how this “change” compares to the sampling error? You’ve gotta read the data beyond their face and consider the circumstances from which they came.

If you want to make some noise, push for higher sampling of non-drive-alone commuters so that you can actually tell who’s biking; at present, you only have noisy, meaningless data to draw “inferences” from.

http://www.stevevance.net/planning Steven Vance

“Push for higher sampling of non-drive-alone commuters so that you can actually tell who’s biking.”

I will also push for higher sampling of non-work trips.

The 3-year ACS estimates (there are two right now) show a different change:
Total workers: 2.31% increase
Males riding bikes to work: 19.41% increase
Females riding bikes to work: 7.69% increase

The ACS will eventually replace the Decennial Census because it will soon (at the end of 2010) the same quality of data (at the county and county subdivision level).

http://www.facebook.com/profile.php?id=513686360 Matt Zanon

A one-digit change in a one-significant-figure statistic implies nothing about anyone’s biking. ACS is a sample, not a census. Have you investigated how this “change” compares to the sampling error? You’ve gotta read the data beyond their face and consider the circumstances from which they came.

If you want to make some noise, push for higher sampling of non-drive-alone commuters so that you can actually tell who’s biking; at present, you only have noisy, meaningless data to draw “inferences” from.

http://www.stevevance.net/planning Steven Vance

“Push for higher sampling of non-drive-alone commuters so that you can actually tell who’s biking.”

I will also push for higher sampling of non-work trips.

The 3-year ACS estimates (there are two right now) show a different change:
Total workers: 2.31% increase
Males riding bikes to work: 19.41% increase
Females riding bikes to work: 7.69% increase

The ACS will eventually replace the Decennial Census because it will soon (at the end of 2010) the same quality of data (at the county and county subdivision level).

http://www.facebook.com/profile.php?id=513686360 Matt Zanon

Think about the math: American Community Survey covers about 250,000 USA households a year. Only .92% of USA households are in the City of Chicago, and only .7% of female respondents, at peak, reported biking to work. So, depending on how many 16yo+ women are in an average household, you’re concluding a change occurred Chicago-wide based on perhaps six or eight women’s change in response.

You should get a job with NYT writing “trend” stories.

http://www.stevevance.net/planning Steven Vance

I stayed away from using the word “trend” or implying the presence of one. The data “suggest” a decrease in the observed activity. I’m currently writing a response to your other comment taking the 3-year ACS estimates into account.

My only conclusion is that we won’t reach the goal in the Bike 2015 Plan, based on the data we have available.

Sidenote: In 2009, 1,917,748 surveys were conducted nationwide, and 80,613 in Illinois.

http://www.facebook.com/profile.php?id=513686360 Matt Zanon

Think about the math: American Community Survey covers about 250,000 USA households a year. Only .92% of USA households are in the City of Chicago, and only .7% of female respondents, at peak, reported biking to work. So, depending on how many 16yo+ women are in an average household, you’re concluding a change occurred Chicago-wide based on perhaps six or eight women’s change in response.

You should get a job with NYT writing “trend” stories.

http://www.stevevance.net/planning Steven Vance

I stayed away from using the word “trend” or implying the presence of one. The data “suggest” a decrease in the observed activity. I’m currently writing a response to your other comment taking the 3-year ACS estimates into account.

My only conclusion is that we won’t reach the goal in the Bike 2015 Plan, based on the data we have available.

Sidenote: In 2009, 1,917,748 surveys were conducted nationwide, and 80,613 in Illinois.

http://www.facebook.com/profile.php?id=513686360 Matt Zanon

Given the one-sig fig “MOI”, how could you tell whether MOI only moved from .015 to .014, or whether the Census Bureau has any meaningfully precise idea about Chicago women’s biking one way or another?

http://www.stevevance.net/planning Steven Vance

Is there an alternate way to gauge how many women are biking in Chicago?

How else can we determine a base line for the goal of “making 5% of all trips under 5 miles by bike”?

http://www.stevevance.net/planning Steven Vance

Check out the updated data in Table 2 (3-year estimates from 2007-2009 were added to show a decrease in women cycling to work, based on a larger sample size than 1-year estimate).

http://www.facebook.com/profile.php?id=513686360 Matt Zanon

Given the one-sig fig “MOI”, how could you tell whether MOI only moved from .015 to .014, or whether the Census Bureau has any meaningfully precise idea about Chicago women’s biking one way or another?

http://www.stevevance.net/planning Steven Vance

Is there an alternate way to gauge how many women are biking in Chicago?

How else can we determine a base line for the goal of “making 5% of all trips under 5 miles by bike”?

http://www.stevevance.net/planning Steven Vance

Check out the updated data in Table 2 (3-year estimates from 2007-2009 were added to show a decrease in women cycling to work, based on a larger sample size than 1-year estimate).

http://www.facebook.com/profile.php?id=513686360 Matt Zanon

Careful with your terminology: the decennial census is just that, a census, so it couldn’t have a “sample size”.

http://www.stevevance.net/planning Steven Vance

I don’t understand – the number of surveys returned is the sample size. Or, do you mean to say that the Census is a survey of the population, and not of a sample size?

http://www.facebook.com/profile.php?id=513686360 Matt Zanon

Careful with your terminology: the decennial census is just that, a census, so it couldn’t have a “sample size”.

http://www.stevevance.net/planning Steven Vance

I don’t understand – the number of surveys returned is the sample size. Or, do you mean to say that the Census is a survey of the population, and not of a sample size?

http://dottiebrackett.com Dream Dottie

This is a very interesting discussion! It’s on my growing list of topics to write about when my day job stops interfering.

http://www.stevevance.net/planning Steven Vance

I know what you mean. Articles that involve some research take longer to write than articles about traveling to New York City (which I did recently – read about that).

I can’t wait for the new American Community Survey data from the Census Bureau. I hope I know when it comes out and I won’t be delayed in analyzing it.

I think what you’re doing “in real life” (the rides, meetings, and women-focused events) is great. Perhaps you’re interested in starting a 501(c)3 to somehow increase the number of women who ride?

http://dottiebrackett.com Dream Dottie

Yes, actually! Since my professional background is in not-for-profit law, I have kicked that idea around in my head, but it’s such a huge undertaking, I have not gotten past the daydreaming part. Let me know if you have some thoughts.

http://www.stevevance.net/planning Steven Vance

You’ll need a board. At least 3 members, I think, from anywhere/any place in society. If you need advice, talk to Randy Neufeld – you know, the guy who had 10 ideas for bicycling in Chicago. He started the Chicagoland Bicycle Federation in the 1980s, what is now the Active Transportation Alliance.

http://www.stevevance.net/planning Steven Vance

Check out the updated data in Table 2 (3-year estimates from 2007-2009 were added to show a decrease in women cycling to work, based on a larger sample size than 1-year estimate).

http://dottiebrackett.com Dream Dottie

This is a very interesting discussion! It’s on my growing list of topics to write about when my day job stops interfering.

http://www.stevevance.net/planning Steven Vance

I know what you mean. Articles that involve some research take longer to write than articles about traveling to New York City (which I did recently – read about that).

I can’t wait for the new American Community Survey data from the Census Bureau. I hope I know when it comes out and I won’t be delayed in analyzing it.

I think what you’re doing “in real life” (the rides, meetings, and women-focused events) is great. Perhaps you’re interested in starting a 501(c)3 to somehow increase the number of women who ride?

http://dottiebrackett.com Dream Dottie

Yes, actually! Since my professional background is in not-for-profit law, I have kicked that idea around in my head, but it’s such a huge undertaking, I have not gotten past the daydreaming part. Let me know if you have some thoughts.

http://www.stevevance.net/planning Steven Vance

You’ll need a board. At least 3 members, I think, from anywhere/any place in society. If you need advice, talk to Randy Neufeld – you know, the guy who had 10 ideas for bicycling in Chicago. He started the Chicagoland Bicycle Federation in the 1980s, what is now the Active Transportation Alliance.

http://www.stevevance.net/planning Steven Vance

Check out the updated data in Table 2 (3-year estimates from 2007-2009 were added to show a decrease in women cycling to work, based on a larger sample size than 1-year estimate).

Sketos

What bicycle mode share means?

http://www.stevevance.net/planning Steven Vance

Bicycle mode share is the percentage of trips taken by bike (there’s a “mode share” for each and every transportation mode).

Sketos

Thank you!

Sketos

What bicycle mode share means?

http://www.stevevance.net/planning Steven Vance

Bicycle mode share is the percentage of trips taken by bike (there’s a “mode share” for each and every transportation mode).